function thisMovie(movieName) {    

//    if (navigator.appVersion.indexOf("MSIE 6.0") != -1) {
//        alert('ie6sucks');
//    }
    if (navigator.appName.indexOf("Microsoft") != -1) {        
        return window[movieName];
    } else {
        return document[movieName];
    }
}

function enlargeDiv(arg)    {
    var obj = document.getElementById('mainnav');
    var p = thisMovie('menu_cos');
    arg = (arg < 44) ? 52 : arg;
    obj.style.height = arg + 'px';
    // obj.style.width = '1200px';
    p.height = arg;
    // p.width = '1200px';
}

function minimizeDiv() {
    var obj = document.getElementById('mainnav');
    obj.style.height = '52' + 'px';
    // obj.style.width = '966px';
    var p = thisMovie('menu_cos');
    p.height = '52px';
    // p.width = '966px';
}